1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

//! Defines helper functions for force Array type downcast

use crate::array::*;
use crate::datatypes::*;

/// Force downcast ArrayRef to PrimitiveArray<T>
pub fn as_primitive_array<T>(arr: &dyn Array) -> &PrimitiveArray<T>
where
    T: ArrowPrimitiveType,
{
    arr.as_any()
        .downcast_ref::<PrimitiveArray<T>>()
        .expect("Unable to downcast to primitive array")
}

/// Force downcast ArrayRef to DictionaryArray<T>
pub fn as_dictionary_array<T>(arr: &dyn Array) -> &DictionaryArray<T>
where
    T: ArrowDictionaryKeyType,
{
    arr.as_any()
        .downcast_ref::<DictionaryArray<T>>()
        .expect("Unable to downcast to dictionary array")
}

#[doc = "Force downcast ArrayRef to GenericListArray"]
pub fn as_generic_list_array<S: OffsetSizeTrait>(
    arr: &dyn Array,
) -> &GenericListArray<S> {
    arr.as_any()
        .downcast_ref::<GenericListArray<S>>()
        .expect("Unable to downcast to list array")
}

#[doc = "Force downcast ArrayRef to ListArray"]
#[inline]
pub fn as_list_array(arr: &dyn Array) -> &ListArray {
    as_generic_list_array::<i32>(arr)
}

#[doc = "Force downcast ArrayRef to LargeListArray"]
#[inline]
pub fn as_large_list_array(arr: &dyn Array) -> &LargeListArray {
    as_generic_list_array::<i64>(arr)
}

#[doc = "Force downcast ArrayRef to GenericBinaryArray"]
#[inline]
pub fn as_generic_binary_array<S: BinaryOffsetSizeTrait>(
    arr: &dyn Array,
) -> &GenericBinaryArray<S> {
    arr.as_any()
        .downcast_ref::<GenericBinaryArray<S>>()
        .expect("Unable to downcast to binary array")
}

macro_rules! array_downcast_fn {
    ($name: ident, $arrty: ty, $arrty_str:expr) => {
        #[doc = "Force downcast ArrayRef to "]
        #[doc = $arrty_str]
        pub fn $name(arr: &dyn Array) -> &$arrty {
            arr.as_any().downcast_ref::<$arrty>().expect(concat!(
                "Unable to downcast to typed array through ",
                stringify!($name)
            ))
        }
    };

    // use recursive macro to generate dynamic doc string for a given array type
    ($name: ident, $arrty: ty) => {
        array_downcast_fn!($name, $arrty, stringify!($arrty));
    };
}

array_downcast_fn!(as_string_array, StringArray);
array_downcast_fn!(as_largestring_array, LargeStringArray);
array_downcast_fn!(as_boolean_array, BooleanArray);
array_downcast_fn!(as_null_array, NullArray);
array_downcast_fn!(as_struct_array, StructArray);
array_downcast_fn!(as_union_array, UnionArray);
array_downcast_fn!(as_map_array, MapArray);
array_downcast_fn!(as_decimal_array, DecimalArray);

#[cfg(test)]
mod tests {
    use std::sync::Arc;

    use super::*;

    #[test]
    fn test_as_decimal_array_ref() {
        let array: DecimalArray = vec![Some(123), None, Some(1111)]
            .into_iter()
            .collect::<DecimalArray>()
            .with_precision_and_scale(10, 2)
            .unwrap();
        assert!(!as_decimal_array(&array).is_empty());
        let result_decimal = as_decimal_array(&array);
        assert_eq!(result_decimal, &array);
    }

    #[test]
    fn test_as_primitive_array_ref() {
        let array: Int32Array = vec![1, 2, 3].into_iter().map(Some).collect();
        assert!(!as_primitive_array::<Int32Type>(&array).is_empty());

        // should also work when wrapped in an Arc
        let array: ArrayRef = Arc::new(array);
        assert!(!as_primitive_array::<Int32Type>(&array).is_empty());
    }

    #[test]
    fn test_as_string_array_ref() {
        let array: StringArray = vec!["foo", "bar"].into_iter().map(Some).collect();
        assert!(!as_string_array(&array).is_empty());

        // should also work when wrapped in an Arc
        let array: ArrayRef = Arc::new(array);
        assert!(!as_string_array(&array).is_empty())
    }
}